Adjustable triggers for rifles have already been proposed, wherein the position of the trigger may be adjusted by mounting the trigger on the body of the firearm, guiding it and displacing it longitudinally on and in relation to a lever-type support that controls the firing mechanism of the firearm.
According to the most common arrangement, the trigger is firmly attached to the support to its desired position by means of a blocking screw. Such an arrangement, however, has several drawbacks, among which is the inevitable, slow loosening of the fastener, with the resultant unreliable operation of the trigger, and the need of available tools for the tightening and loosening of the screw whenever it is desired to vary and regulate the position of the trigger.